There are many reasons to insulate pipes, fittings et cetera. One of the most important reasons for insulation is to save energy during the conduction of materials through pipes. Many manufacturing processes require the transportation of liquids and gases through lines at a specific pressure or temperature without reheating or cooling. Also, many processes demand the uninterrupted maintenance of certain temperatures to facilitate the movement of caustic materials or corrosive substances through the pipelines.
The internal make-up of valves and accouterments, themselves, can contribute to a pressure drop within the pipeline, decreasing the velocity of the substances transported and leading to substance "caking" or build-up within the valve. In addition, the chemistry of many processes demands that internal temperature be maintained within very rigid requirements. Contributing further to the problem, is the fact that the function of many pipe lines dictates their exposure to the extremes of weather change occurring outside factory buildings. Today, freeze-ups occur every winter and cause loss of production in many plants, even in the Southern parts of this country.
The use of various devices to insulate pipe accouterments is well-known in the art. A two-part metal insulating shell is disclosed in U.S. Pat. No. 1,108,840. The two portions of this shell are adapted through custom manufacture to fit around the accouterment and mate with each other by means of interlocking flanges. The device is adapted to form collars or rings which receive asbestos packing as the insulating agent.
A major drawback of this device is the need to obtain the exact measurements of each accouterment prior to manufacture of each custom-fit insulating shell, causing attendant delay and additional expense. Another drawback is the limited usefulness of asbestos an insulator, both from the standpoint of its safety and efficacy as well as from its sporadic placement within the metal shell. The present invention addresses these problems by providing an inexpensive standardized jacket which only becomes customized upon application rather than at time of manufacture, and which utilizes the superior insulating and safety features of a closed-cell polyurethane foam insulating layer uniformly enveloping the accouterment.
U.S. Pat. No. 3,724,491, discloses a device for insulating pipe accouterments which is composed of a plurality of metal sections which mate together to enclose the accouterment.
Each section includes an outer metallic sheeting to define a space therebetween into which insulation material is provided. The metal sections are removably connected together around the accouterment. Because the inner sheeting is formed of metal the shell does not fit the exact contours of the accouterment.
It is also necessary in the above invention, to permanently attack and maintain a clamp to the device to maintain an inward pressure against the pipe. The present invention solves these difficulties by providing the superior insulating qualities of a closed-cell foam, not allowing for vapor penetrating of the foam layer, not allowing the insulation layer to become exposed or degraded upon removal, and eliminating the necessity of a clamp during use.
U.S. Pat. No. 4,207,918 discloses an insulation jacket made of fiberglass fabric and containing a plurality of parts including a skirt, jacket and cap. A flexible mat inner layer is provided for insulation, and the jacket is strapped to the pipe. Drawbacks inherent in this device are that the flexible inner mat layer has a tendency to "settle" in response to the forces of gravity and can degrade upon exposure of the jacket to caustic substances. Gaps can occur throughout the jacket layers in areas where the straps cause folds to occur in the jacket layers. Additionally, customized manufacture becomes even more necessary due to the fact that the jacket is composed of a plurality of parts. The present invention addresses these problems by providing a standardized one-piece jacket with a non-settling and non-reactive insulating layer which molds to fit to the exact shape of the underlying accouterment without exposure to the atmosphere or degradation.
U.S. Pat. No. 4,448,218 discloses an device which is used to seal leaks in pipes through the use of a rectangular inflatable rubber pad. This device is not particularly germane to this invention as it contemplates "patching" pipes rather than insulating pipe accouterments. It utilizes air which has almost no insulating properties and also is not suitable for application over sharp and irregular-shaped accouterments which could easily puncture the rubber exterior.
U.S. Pat. No. 4,556,082 discloses a unitary and removable insulating jacket for accouterments having inner and outer layers composed of aluminized and siliconized fiberglass material, and containing a 1" thick fiberglass middle layer. The jacket uses drawstrings to wrap the jacket in a diaper-like manner around the accouterment. Although this cover does have the advantage that it doesn't need custom manufacturing, there still exists a major drawback, because it does not conform to the exact shape of the underlying pipe accouterment. This gaping then leads to the formation of pockets of air between the insulating jacket and the pipe where pools of liquid may collect within the jacket itself causing degradation of the middle layer.
None of the foregoing inventions teaches a standardized one-piece insulation jacket which utilizes a heat-shrinkable inner layer in combination with a relatively inflexible outer fabric layer to form two oppositely-positioned pockets adapted to contain a middle layer which is created and formed at the time of application. Nor do the foregoing inventions disclose an inexpensive closed-cell foam insulating jacket which can be molded precisely to the shape of the underlying accouterment, without exposing its inner layers to the environment, without being custom-designed, and without allowing its insulation layer to settle or degrade, even upon removal from the accouterment.